The present Invention is directed to a device for insuring that a predetermined number of planar products is included in each stack thereof; more specifically, the device accurately counts the products so that stacks of desired size, previously not achieved by the prior art, can be obtained.
Devices for handling planar products (usually newspapers) include those wherein the newspapers are stacked and bundled.
In the past, planar products (such as newspapers) have been imbricated on a flat conveyor belt and carried past a counting sensor. However, this is difficult to accomplish with any real degree of precision because of the variations in the relative locations of successive papers. As a result, there is a tendency to intentionally over stack in order to insure that the recipient gets at least the minimum number required. Alternatively, if the correct number is targeted, a real danger exists that some dealers will end up being short.
The present Invention is directed to a device whereby an accurate count of planar products, as well as an accurate count of the contents of each stack thereof, is readily obtained. Although the present Invention is useful in connection with the handling of planar products in general, especially those which are sufficiently flexible so that they cannot support themselves vertically, the description will be directed to newspapers.
The present Invention is a device for stacking successive newspapers, carried along a feeding path, into pluralities of individual stacks, each of which contains a predetermined number of papers. There is provided a circular conveyor, mounted on a rotatable support, and having a plurality of circular conveyor grippers spaced apart from each other by a circumferential distance. Each of these grippers carries one newspaper and is adapted to release at a stacking point.
There is a sensor, adjacent the feeding path and located at a counting point. The sensor is adapted to count each newspaper as it passes the sensor and while they are spaced apart. The distance between them remains substantially unchanged as the papers move from the counting point to the stacking point. In this manner, the sensor can readily and accurately count the papers since they are individually held and spaced apart from each other. The fact that the papers are counted when they are individually and separately held, and the distance between the papers remains substantially unchanged until the stacking point, insures that the same number counted by the sensor is included in each stack.
In a refinement of the Invention, the circular conveyor grippers release the predetermined number of successive newspapers so that they land on a first receiver. As this occurs, the receiver moves away from the stacking point along a stacking path as the stack is built. Preferably, the speed of movement of the receiver corresponds to the newspapers being placed thereon so that the stacking point remains in the same position relative to the circular conveyor.
It is also within the scope of the present Invention to provide a linear conveyor, having a plurality of spaced apart grippers, each of which carries one of the newspapers along the feeding path. The spaced apart grippers release the papers at a transfer point adjacent the circular conveyor, whereby they are transferred from the spaced apart grippers to the circular conveyor grippers. The distance between the spaced apart grippers and the circular conveyor grippers is preferably the same.
Here, too, the receiver previously defined can be placed adjacent the stacking point. Also, it has been found advantageous to provide a plurality of fingers which individually compress the leading edge of the newspapers as they are placed on the receiver. This results in a particularly compact stack. There can be a plurality of sets (pairs) of fingers which successively compress leading edges of successive newspapers. This enables the fingers to move more slowly, thus saving wear and tear on the device. Alternatively, a second receiver intercepts the stream at the end of the prior stack and starts building a successive stack. The prior stack is thereby compressed between the second receiver and the first receiver.